A Maryland man has died of rabies after receiving an infected donor kidney 16 months ago, prompting the Centers for Disease Control to test three other recipients of organs from the same donor.

The CDC said the additional recipients, who received organs including the heart, lungs and kidney from the infected donor, were being tested for rabies and given anti-rabies vaccinations and immune globulin as a preventative measure.

Maryland state health officials had called in the CDC after the man's death to determine if the cause of his rabies infection was linked his kidney transplant. CDC officials discovered the same strain of rabies in tissues from both the organ donor and the recipient who died.

CDC spokesperson Barbara Reynolds said the donor had signs of encephalitis or brain swelling at the time of death, but was not tested for rabies because of the rarity of the illness and the length of time it would take for the test to be conducted. There was no information on the official cause of death of the organ donor.

"There is not a viable test at this point in the time frame that this is done," said Reynolds of the short window when organs are usable for transplant. "Rabies is rare as a human disease in the US. It would be extremely rare to occur to organ recipients."

Rabies only affects a handful of Americans each year. Although thousands may be exposed to the illness, if treated with preventative measures and vaccines they will not contract the infection. However if not treated preemptively, the rabies virus is almost always lethal.

In 2004 three people died after receiving organs from a donor infected with rabies in Texas. According to the CDC that was the first known time rabies was transmitted through by solid organ donation, though the disease has been known to be transmitted through cornea transplants.

Doctors were also confounded by the excessively long incubation time in this case. While rabies usually has an incubation period of one to three months, the Maryland man who received the infected kidney showed no signs of the disease for 16 months after the transplant.

Dorry Segev, a transplant surgeon at Johns Hopkins Hospital who was not involved with this case, said that it was not uncommon to transplant organs from a donor that was suffering an unspecified infection with symptoms such as encephalitis.

"Often it's not possible to get a definite diagnosis, then you have to use your judgment," said Segev. "There are certainly donors used every year, where there was a possibility that the donor died of an infectious encephalitis and the organs were used."

Segev says that because of the rare number of rabies cases and lack of information about rabies transmission through organ transplantation, it is unclear whether the other organ recipients would also be infected.

"This is an unusual situation, no one knows if there 100 percent transmission of rabies from donor to recipient," said Segev.